Beet topper



June 9, 1953 N. E. REYNOLDS ET AL 2,641,099

BEET TOPPER Filed April 19, 1946 8 SheelZS--Shee'l'l l /5'2 QQ tra@ ray-J' June 9, 1953 N. E. REYNOLDS ET AL BEET TOPPER 8 Sheets-Sheet 2 Filed April 19, 1946 n lo( l I e. o obevt (maison Q gecn @ne )Q gl( vromvaya June 9, 1953 N. E. REYNOLDS ETAL BEET TOPPER 8 Sheets-Sheet 5 Filed April 19, 1946 gYllds QQ, Q. CYnc NVE-NTOK 19h69, 1953 N. E. REYNOLDS ETAL BEET TOPPER Filed April 19, 194e s sheets-sheet 4 Cnelson )Qegnolds Xeon Q cmcQobQrf Mn @4f-MMM @k TTOwYJ June 9, 1953 N. E. REYNOLDS ETAL 2,641,099

BEET TOPPER Filed April 19, 1946 8 Sheets-Sheet 5 5). {QI-T I mtv-*rana e son l. QQ .molds @e @on Q, @me @bwk Mmgmwww 'no @1mo- N. E. REYNOLDS ETAL June 9, 1953 BEET TOPPER 's sheets-sheet e Filed April 19, 1946 llaga,

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June 9, 1953 N. E. REYNOLDS E'r AL 2,641,099

BEET TOPPER Filed April 19, 194e v s sheets-sheet 7 L POINT AT WHICH KNIFE ENTER LAGI l TABLE sHcwlNc LocATloN or KNlFE RELATIVE To FINDER Fon vAmous nza-r alzas (ron vsn-nem. 12A-no mn Cnn-msxaen- LAG ou csowu euml GAP novum am Hamm' cnowv'v MILT RAolu CENTER ADVANGE on Awve. TmcuNz-:sa DIAMEPIR LINE ONCENTIR UNI Cm LINE MIDPLNB |.o 0.5 om o`.oo om o.ao 0.68

ao 1.o 0.42 ooo mz Lsa 0.9

4o zo aan alo 2.74 :J9 La? 5.o .as Los 0.14 am 5.98 1.60

6.o ao :.za o la I 4.|o mv Las 7.o as 1.44 oas 4m 5.55 oe /f/g/o l NvaN-rorz glelsonQd@ 'ngld 6011 C O er' um @www fhg June 9, 1953 N. E. REYNOLDS ET AI. 2,641,099

BEET TOPPER Filed April 19, 1946 8 Sheets-Sheet 8 ARM POSTIONS CORRESPOND TO BI-:ET DIAMETER (D) 4 INCHES ll cnowN cugym'une Amance .l l

*md LEVEL OF FINDER r I nvnL or n ure; H D mvg. or moge L MIDDLANE r r I.evs\. or Ian-CH /52 cRowN -rIIIcKnEss cfr. .4s haan SINCE. H=.eD' 7 f u1'. .45+ .29H

= L37 FOR 4" DIA.

(Avromyd Patented June 9, 1953 tri-1,6%

BEET TOPPER AnplicationAprillB, 1946,. Seria1..No...66i3,5,12

.=9 Claims. 1 (Cl. min-121:46)

1 This vinvention yrelates to a method of --and meansior harvesting beets. v`More"particularly it is concerned with beet "harvesting `equipment adapted to remove the `tops yof beets-and, after a replacement of .a portionof-the yapparatus, to remove the' topped kbeets lfrom the earth.

Attempts have been made-over a long-period of y years to Yprovide ,harvesting apparatus Yenabling the harvesting Aoi"beetsin1a --manner completely satisfactory tothe beet growers. The-fact that themajor shareofsugarbeets havefin spite of such attemptscontinued tobeharvested largely by hand is evidence of thef'iact that no'machine satisfactory to'the `'beet grower has Abeendeveloped. In addition to the mechanical'shcrtcomings y,of prior 'beettopping and digging apparatus, there hasbeen alack `offullappreciation in the art' 'that the :beet-tops or-.foliage isv ava'luable crop which should be har-vested and immediately removed'frcm contact witlrthe earth'or-other-source of contamination A'for `subsequent use asa stock feed ohigh food value. 'Judging'by prior art'devices, 'there hasalso been a failureto'consider the removing and retrieving of thebeettops and subsequent removal and -retrieving of the AVbeets as .a vdouble harvesting-operation Which-maybe economically vaccomplished by the useof the two separateattachments in association'with abasic conveying-supporting V-mechanism employed in both thetoppinganddigging operations.

With regard to thetoppingof tthebeets,fthe desirability Vof in place topping h-as-beenrecogniued' but no machine'thusfar developed has'been found in practice lto `be'ffounded en principles oiiering a completely satisfactory solutionfto fthe problem. -Prior machines, particularly when used over somewhat irregular beetelds vare undependable, v'easily `jam-medV and generallyerratic in operation. For example, in the case of aflarge portion oi the beets, vtoo-little crown-may'be'r-emoved vthereby increasing the tare and reducing the price which thebeets shouldcommand on the market. "if, as joccursfrequently, too great a portion ci the tcp ofthe beet-is removed-this obviously results'in a-'tonnage loss inthe J.beets than can he gathered from la'single-acre. It Yhas been commonexperiencein the use of'beetztopping maohinesthat beets are pushed'over,broken, and ineniciently cut and removedfrom the earth.

It is not diflicult to see Why'such maloperation has .been prevalent. essaryto.properlygauge them to .determine .the line of clit; and euch gauging. generally haslheretofore .been feiieeted lwith reference `.only ,to .the beet being topped and Without reference to the ditch or ridge level. It has been foundthat 'for accurate.topping, the crown thickness to be removed lfromiany beet must be determined with reference to some gauge level. For .accurate gauging, however, the ground suriaces'nearest'the beets are not suitable because the ditches are uneven and vary in depthirom eld to eld. Moreoveryifthe'iield is on a slope, erosionireguently Washes a ditch deep at one end, lling'it up" level at .the other. The ridges .too are uneven `both from natural causes and from the practice of some growers to throw dirt in around ther-stems to cause. a concentrated stemgrowth. Additional difficulties arisefroin the fact that the beets may be located-several inches to either side of `the actual center line of the row, either because vof inaccurate planting lor displacement 'due to'the subsequent tillage. Further, in harvesting, the extremely ,dense foliage peculiar to sugar beets tends to clog orrjam variousportions ofthe mechanism. The lower leaves particularly, which are iibrous and Iropy when somewhat wilted, interiere with the desired operation of the device.

It is themainzobject of thepresent invention to'provide new and improved apparatus adapted to a. novel method of harvesting whichincludes the Ycutting .and retrieving of the beet tops andthe subsequentdiging andretrieving of the beets.

'It is an object ofthe invention toproduce a. beet harvesting mechanism "which is simple, economical to operate and will give consistent results under adverse held conditions.

AIt is another object4 of our invention toprovide means for gauging automatically and accurately the correct amount of crcwnto *be slicejd 'from any y'beet ,regardless .of its diameter orheight above' the .ground level.

It is a'further object oi our inventionto supply meansin combination .with the beettopper for determining a mean or articial, ground levelffor use as algauging reference plane.

Still .another object is .toprovide a simplified mechanism which employs a iinder for 4.gauging theheightof the beetanda beet .topping .knife so constructed andinterconnected bylinkagethat the.. movements of .the iinder .andthe knife, .both vertically and horizontally, `will .he according .to certain. deniteand .predetermined requirements.

A still further object of the invention .is -to employscutting means. eiiective .to producet aslicing. action for cleanly. severing the .beet with .a minimum .tendency .to produce `breakage or vdisplacement .of the beet .regardless of `type -of `soil andunder .widely .varying moisture. conditions.

It is yet another object of the invention to produce means for centering the gauging and cutting mechanism upon individual beets to enable uniformly efcient topping in spite of beet misalignment.

It is an additional object of this invention to provide for the gauging and topping of either small or large beets with no tendency on the part of the gauging mechanism to override the smaller beets or underride the larger beets and thus cause inaccurate topping or beet breakage.

It is an object of this invention to provide beet harvesting equipment which has a minimum tendency to jam or otherwise to be aifected by the dense foliage peculiar to sugar beets.

It is a further object of the invention to employ novel structure for use in association with a power lift device and a plow for digging beets whereby the plow is elevated for transportation in a manner to produce a large margin of ground clearance and to provide maximum protection from damage.

It is a still further object of the invention to provide a conveyor adapted particularly for transverse mounting on a farm vehicle which is adapted for discharging conveyed material on either side of the vehicle.

It is still another object of our invention to employ structure associated with a digging plow and conveyor such that transport of beets into engagement with the conveyor is accomplished in a uniform manner for all depths to which the digging ploy may be adjusted.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings, in which- Figure 1 shows a tractor equipped with vertical supporting members and transverse conveyor mechanism embodied in one unit of our invention.

Fig. 2 is a general view showing the topper attachment and loading mechanism used in conjunction with the device shown in Fig. l.

Fig. 3 is a perspective view of the digger attachment and elevator showing the method of association with the tractor and transverse conveyor.

Fig. 4 is an enlarged view in elevation setting forth the details of the topper unit of Fig. 2.

Fig` 5 is a simplified view of the finder and topper linkage of Fig. 4 showing the knife in the raised position immediately prior to the topping of a beet.

Fig. 6 is a plan view including structural details of the mechanism shown in Figs. 4 and 5 with certain parts broken away.

Fig. '7 is a more detailed view in elevation of the conveyor mechanism with parts broken away.

Fig. 8 discloses the power transfer scheme for driving the loading and conveying apparatus from the power take-off of the tractor.

Fig. 9 shows the method of geometrical construction employed to determine the proper horizontal gap between the finder and knife.

Fig. 10 is a table outlining the proper space relationship between the 'finder and knife under a given set of assumed conditions.

Fig. 11 is a diagrammatic representation of a simplified linkage following a law of operation as determined by the data included in the table of Fig. 10.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that we do not thereby '4 intend to limit the invention to the specific form dlsclosed, but intend to cover al1 modications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Prior to a description of the novel apparatus which we employ, it will be helpful to set out the more basic requirements of a satisfactory beet harvesting device. It will then become apparent as the discussion proceeds that the harvester which we have produced is inherently able to satisfy these requirements.

The first requirement of beet harvesting is that the harvested crop be fully utilized and that harvesting be performed in a manner such that the crop will be of maximum value to the grower.

A second requirement is that the harvesting shall be completed in a minimum of time and with a minimum expenditure of manpower.

A more specific requirement relates to the level of topping, in other words the determination according to beet size of the desirable thickness of the crown to be severed. It has been considered desirable to have the small beets cut at the lowest leaf scar line, and in large beets it is desired that such cutting take place about three-fourths of an inch below the lowest leaf scar line. Investigation carried out under the supervision of the University of California, which resulted in a large amount of data, has shown that the proper rise of the finder with respect to the knife should follow the ratio l.4:1.0. Under certain circumstances where it is desirable to produce a thinner crown, ratios of 1311.0, 1,211.0 and even smaller ratios may be used. Correlative with the above it has been observed that as beets grow they increase in height above the field (as of at planting time) in a rather close relationship to their greatest diameter, the average height of the beet crown being about of the greatest beet diameter. If, as in irrigated territories, the field is furrowed out or ditched an average beet will grow in this same ratio of dimensions relative to the midplane level between the ditch bottom and the row crown top since substantially the dirt removed from the ditches between the rows has been deposited around the growing beets to form a ridge. The term mid-plane, which is also used elsewhere herein, is defined as an artificial reference plane at a level midway between the ditch bottom and the ridge top. That the above data may be incorporated in a relationship which may in turn be utilized to control in part the operation of novel beet topping mechanism will be more fully covered later in the discussion.

Another more specific requirement of beet harvesting is that the beet top or foliage not only should be salvageable but should actually be harvested and kept free of dirt, thereby producing a stock feed of high food value. Further, the beet roots should be dug and loaded with a maximum of efficiency and a minimum of damage.

A still further requirement resides in the desirability of reducing both the complexity and amount of equipment required to perform the complete harvesting operation. Closely allied with this is the requirement for maximum portability over various types of terrain to the harvesting location.

Three basic units are employed in our beet harvesting apparatus. The first is a conveying-supporting unit I5 fixed on the tractor I6 (Fig. l) which is consecutively associated with a topping .cicatricesn` attachment 4or .unit iI .fl tas in Fig; 2.1).. `.and a digg-iris attachment on unit t8 .(asfin i Ilia.;y Bil., Yas required f by the process orharvesting` y Both theetoprping and digging attachments `disclosedrare capable Aof harvest-ing .the :beets in two adjacent rows lsimultaneously. This feature enables twoipasses :tobe made i -over the viield, Athe :first lfor topping, the

second .for di.gging-in .the sameitime oi'siless time than :would :betre'quired by a beet.v haryester which the topping, digging and retrieving of the beets .froml a.-single -row lis acdcmplishedwby single harvesting assembly.`

The speciiic tractor yhere 4sl'1own-.vvill be recoge nized by those skilled in fthe-art .as a. familiar.

herenteinthis .typeof hitchtobe realized.- y Among,

these .advantages l may bey included the-.stability nrovided by the .upper andlower links lof the Fergusonhitch, .suchlinks .enabling -the'topller or dig-ger devices to become a .structuralunit with.;

the -tractor. In addition, theEerguson hitch en-l ables `the level of .theharvesting devices `to. be readily adjusted .respect tothe vehicle. With the vehicle and harvestingdevices-in-apredeterrnined verticalirelationship.the necessity ,for

gauge Wheels to engagethe ground iszelirninated, the vehicle itself beingsubstituted therefor. .In the .case of .thedigger unit,.auto1natic verticalad" justment of the .dggerelement .isdeterrnined by the .reactive .forces acting vin .compression onthe upper link. Movementnf -a .manual .control-on the other .hand enables .either harvesting unit tobe raised .clear .of .the ground ,for purposesoi transportation. vWe wish'itunderstood, however,

that the harvesting apparatusandmethod which. A We disclose isnot in Vany vvayrestrieted.to ,use with the Ferguson typel oi'hitch and, .as Wilt-appear to those skilled in the art, the .harvester disclosed.

may also be used with other-.typesio tractors.

:Conveying-supporting unit form consists of-a conveyorand conveyor-'support' together-With couplings tto lengage'feitloer thetopper unitorfthevdigger'unit. The Ferguson hitch includes a lov/er pair fof flaterallyspaced-draft A linkslil,..2lpivotedfat theirfforward ends"'beneathv and .for-ward4 of the. .tractors lrear faxle. These linkspare suspendedby droplink-s 23'lfrom-cranks 22 -rigidwitli afroclcgshaft 22a: The .latter is oscillated'by a hydraulic. ram .(notrshown). as .is t customary in the systemyof Ferguson Patent No..

2,118,180. For thepresent, suficeit to `:say .that pressure .iiuid may `be admittedto or' exhausted from therein-under the-'control ofa main-.control valve (not shown) ioperableby a quadrant lever 24 to raiseand lower.the-linkstil'. More.

over,vcornpression on athirdor,` top link 2.5.;serves ef veniende may ibe :monntedbn the tractor kutilizingthe bolts'normaly.emnloyedto mountthefenders i 0f 'the fvhlidle l. Spitrrningthe top :of:V :the `upright subpart/:is "a l transverse horizontal :conveyor indi. cated generallybythe-:numeral 3i -Thiswoone vieyer isarrangedwto'bev-translated v.either to :the

righ-toritofthe left. swillbembref llyzdiscussedf inorder ftofeiect @conveyed material .well `over the side of theftractor;

As sloivnr-in Fig'f fain eleval'fiollrll xvii-ew taken: from: ftheifront .ofy :thepftradtozlt `theconv@tv orl` mountedat the/.tenor thesnprorti-ns columns i251 and ,3,5 includes -1.a laterally 4sutiable :fratrie 49:: lvlcuntsdat` 1the rends ,of the frame lare rotatable shafts 4l and 42, over which is trained an endY less conveyor belt V4.3 driven respectively by sheaves 33 and 39.. YIn order to more rmly engage :the conveyed material, the smooth surface of thek conveyor lbelt is interrupted `bycleaitspor ridges 44.` ',Io 'facilitate vsliding movement', the frame "4Q `mounted between' rollersd and llt journaled oirtheA uprightk "brackets 118 andA 5D secured tothe lsupporting 'members 2 3 'and 13B.' The `conveyor 'is -mai rita-ined in one `or *the other oi the-extreme'vpositions'by means oilatchmeche ariisrns'iril andes? Which-'have"pavvls "'fand '5d respectively: Patti-engagingprojections 5in mounted'fonithe side offth-ef-sliding-fframe are engagedu bythe pawls to determine `the-'extreme limits of seen, serve to lreepftlie appropriate one 'of i apair of `driving belts taut.

Attached-to the right Aend 5of the sliding fra-me is a hand rope `458; the'other-end-o'f Which-is Aconnected vto i, the bracket Y60.` Thisy '-rope Vv'is' ladapted tof-beY pulled in'forder "to urge vthe vsliding frame into theileft-hand positionas villustrated- A fhand rope (il4 is similarlyconnected to lthe opposite endfof` the sliding frameto move the frame tok the-opposite position.'

Instead `ofbeing 'connected directly toHthe; bracket lshown, the vends of the hand ropes 5'3 and 6| may be passed once around a longitudi-` nal drive shaft 1B and'the 'free end of'each rope terminatedinahand grip; It is obvious that by so :doing the'rotating'shaftl'may be made toserve as 1a hwinch; Simply tensioning 'the ape propriate-ropeabout thep-driveshaft by a manual pull would beeffective to transport the conveyor.v frame fromione extreme .position pto 'theother "Before'lateral movement ofthe movable 'frame can occur, "however, .itiis.necessary to applyiorce to the .pendant 63 thereby to disengage the pavvl 53; from .the .stop.156, the 1pendant .16 4 periorming the equivalent function when .the sliding vframe in .theopposite extreme position.

Power is transmitted to .the `conveyor .belt .431' with.theframel in ,the position shown .by means.-

. of a driving beltli.` Anlalternatively used-belt' ward .againstthe bias. of f a control spring vTI rand i eil ect anexhaust .of .uidfroin the;ram,xall3. in 1a manner to retain automatically a constant coin.-v

pressive `force in .thecontrol-spring.

Mountednear the .rearV or the itractor', prefere ably over the 'rear axle, .arezuprght:supporting.

columns` 28 .and- 3l! which :for .l the sakeaof con 68 ,is ,provided .for driving the conveyor .belt ,with

the ,frame 4.0 oppositelyextended,.tli6:belt notin f user-,being maintained .in `contact withits ,sheaye bya .retainer ,152.. .It -vvillbe noted thatthe belt 68 .has-,a .single .twistin order to .drive i-the con-v ,veyor'beltz .4-3 :in the opposite. direction. .The belts 66- and 68 are driven` by a double sheave 455` I mounted on a .longitudinal lshaft l0. `Power. fis i conveyed to'ithegshaft 116 by meanslfof. the belt.' 'Il' ydriven'fbyv the Apovvewtakeeoif pulley `L2 l(see 1 ,Fig` f4-1) on .the usual `power take-'off .l atttherear end ofcthe tractor.

Attachment :of 1ther'upper:end `.oi-an elevatorto y f -1 remainder of :fthe support aioided 'the elevatorL is provided by the lower links of the Fergusonv hitch. It will be seen, particularly in the discussion concerning Figs. 2 and 3 which follows, that the elevator, regardless of whether the beets or the tops are being retrieved, is supported in such a manner that raising of the lower links may be employed to lift the lower end of the elevator clear of the ground. An additional member mounted on the tractor and adapted to engage the elevator is a yoke 14 which serves as a limit stop to limit the upward or downward movement of the elevator. A further function of the yoke in the controlling of the hydraulic lift mechanism will be discussed in connection with Fig. 3.

Topping unit The topping mechanism indicated generally by the numeral Il is shown generally in Fig. 2 and in greater detail in Figs. 4, 5 and 6. Two identical topping assemblies 18 and 19 act simultaneously to top the beets of two adjacent rows. Since the units are identical, a description of the unit 18 will sufce for both. As the discussion progresses, it will be seen that the apparatus l1 as a whole has three primary functions: The rst is the establishing of an artificial reference plane from which the height of the crown of the beet may be measured; the second function is that of adjusting a topping knife with respect to the reference plane in accordance with certain principles to be described, and cutting the crown portion from the beet; and the third function is that of retrieving the beet tops.

The first function, that of establishing an artificial reference plane, has to do with the midplane defined above as the horizontal plane lying midway between the ridge top and the ditch bottom. The use of such midplane as a reference level in setting the topping knife averages out the vertical irregularities of the ditch and the ridge, thereby increasing the accuracy of the topping operation.

As the rst step in obtaining an artificial reference plane or level, the beet topping mechanism as a whole is maintained in fixed vertical relationship with respect to the vehicle, it being assumed that the wheels of the vehicle run in the trenches or ditches between the beet rows. The basic supporting element of the structure is a horizontal tool bar 80 (Fig. 4). This tool bar is Iheld in place vertically at a predetermined level with respect to the tractor by the draft links 20, 2| and 26. Brackets 8|, 82 and 83 are rigidly connected to the bar 80, the bracket 8| being pivotally connected to the upper link 26 and the brackets 82 and 83 being connected side-by-side to the lower links 20 and 2| respectively. A check chain 25 may be used to limit the downward movement of the lower links 20 and 2 I.

In order to afford each beet topping mechanism a limited amount of lateral swing, an upstanding support 84 is connected rigidly to the horizontal bar 80. Mounted within the vertical support 84 is a shaft 85, the ends of which are journaled in rotatablesleeves 8'! and 89. 'I'hese sleeves serve to support cross members 9| and 92 respectively. Trailing from these cross members at the upper and lower ends of the support 84 are a pair of horizontal links or levers 88 and 90. The trailing ends of the links 88 and 90 are pivoted to a vertical link 93 which coacts therewith to complete a parallelogram 84, 88, 93, 90.

Suitable means may, if desired, be `provided to bias the topper mechanism into alinement with the longitudinal axis of the vehicle. Thus a centering spring 95, which preferably takes the form of a leaf spring is fastened rigidly to the bracket 9| to engage a forked upstanding member 96 mounted on the horizontal bar 80. It will appear obvious that centering coil springs may be used, if desired. v

Vertical positioning of the link 93 of the parallelogram 84, 88, 93, 90 is determined by L-shaped gauging runners |00 (Fig. 4). Movement of the latter causes the links 88, 90 to assume a corre-v sponding angle of inclination thereby controlling the pivot level of the topping knife arm and nder arm. Such gauging runners are arranged. to contact the ridge or crest of the beet row, holding the vertical link 93 at a level which is a function of the ridge level.

While the present embodiment uses runners for riding the ridge, other forms of ridge riding or feeling members may be used which accomplish the same function. Such members may, for example, consist of wheels, the axles of which may be fixed to the vertical link 93 for controlling the lev-el thereof. Support for each gauging runner |00 is provided by the rigid extensions |02 of the link 93. The gauging runners are arranged in .pairs which converge inwardly until at the trailing ends the separation is approximately equal to the diameter of a sugar beet of average, or slightly less than average, size.

In order to allow the gauging runners |00 to spread apart to allow passage of a larger than average beet, Iprovision is made for a limited amount of swiveling about a vertical axis. Such swiveling is permitted by the mounting of each gauging runner |00 in a vertical sleeve |04 fixed at the end of the rigid extension |02. Outward movement of the gauging runners |00 is resiliently opposed by the compression springs |05 (Fig. 6) urging the arms |06 inwardly. In acoordance with our invention, these gauging runners have two primary functions. One of these functions is to center the finding and cutting mechanism upon beets which may be located several inches from the center of the ridge, such centering being produced by swiveling of the mechanism about the shaft 85. The second function is to maintain pivot-supporting members ||0 to which the knife arm and the finder arm are connected at a level which is proportional to a mean level (midplane) between the level of the -ditch and that of the ridge. In the present embodiment, the pivot-supporting members ||0 are rigidly fixed with respect to the horizontal links 88 and 90 ofthe parallelogram approximately at the center of such links. A transverse brace 88 interconnects the members ||0 to insure that both sides of the parallelogram act as a unit.

Normally the weight of the topper assembly tends to press the gauging runners |00 into firm contact with the earth. In order that the downward unit pressure might not be too great, horizontal vanes |0| are fastened to the runners. In addition, part of the force is counterbalanced by a tension spring H3 anchored at diagonally opposite points ||4 and ||5 on the parallelogram linkage. The spring ||3 is mounted as shown merely for purposes of convenience and, as a matter of fact, any anchoring points could be chosen which would have the effect of reducing the pressure between the gauging runners |00 and the earth.

The pivot-supporting members |I0 carry two pivots ||6 and ||8. Trailing downwardly and rearwardly from the pivot I8 and engaged therewith is a finder arm |20 which carries at its lower necting link E31.

end a iinder disc` 121. f This disc is centered between the gauging runners 00 inthe vicinity of the trailing tipsof the-runners. Forward v'movement of the topper mechanism causes rotation of the ldisc |24 about 'thefpivot point l122; this rotation combined with the thin constructionof the disc venables the ylatter to penetrate the foliage and contact the crown-'of each beeft 'in the row.

Supported Vfrom the upper pivot H3 is ali-nire arm 123 havingan upper portion 24 'and a lower `por-tion y25. Connection between vthe upper portion Ill!! and the lower portion 125 is eected by Va `knife arm 'clamping vplatelllt having clamps `"|'2`8 allowing adjustment of the lower portion 125 'of the 4knife arm with respect to 4the `upper portion. Downward movement of the knife arin about the pivot Hi8 is limited `byf'a stop 'illadjusta'bly mounted with respect fto the vertical. links 93. Movement of the koi-'5e arm H23 about the pivot il l 8 is controlle :l lby lthe elevation ofthe fonder disc l2! 'through the me'diumfof the con- Upward movement of either the knife armor vthe finder arm is resisted :by'a lspring m2 which tends to urge the knife arm tilt .into contact withth'e adjustable Vstop i3d.

Mounted=at the lloivernen'd of the-knife arm 1'2'3 is .the topping knife 'indicated generally bythe nun'i'eral .1311. .ills (shown in the knife has aflat substantially .horizontal Iblade 135 which preferably extends obliquel-y to 'the ldirection fof .motion-of the topping mechanism. 'The elevation angle of thefknife -blade |35 fior fgiven position of the yknife-.arm maybe adjusted Within Ilimits by the adjusting ymeans fl'i.

The `angle ofthe knife kr.withires-pect to the diirection of motion lis .shown in ithe 'drawings to fbe rapproiirnatelyl". Although this value has been found to produce a very satisfactory cutting action, it "will be. :apparent to zoneiskilled in the art thatra'n angle greater or less thanithisraniount maylbe used. :The .useof asknifeihaiiing:consider- Jable width rand mounted vdiagonally uis .accompanied .by .a number .of advantages which-have 'been :found to lbe zran .important.factor in '..the f successful operation-'of fa topper .of aour idesign.

We :have 'found lit desirable .for zaccurate .'topping, for the vknife l.blade :to renter :the V:beet at the instant that the finder reaches the high point of the crown. The factors to be considered theudesign of 'the :apparatus 'in 1,order `that `this condition amay obtain Aare @outlined in f'detail 'later yin the discussion. It "would fiappear that as the 'finder disc vis fdrawn Ebeyond the crown of lthe'lbeet, the resultant flowering 'of thedisc would itend fsimultaneously rto lower the knife. As amatter of `fact,:because of the widefangular .blade "and the `horinontal application -ro'frthe fouttingfiforce, the cut'tcnds toremainfat the initial level vinste'd of proceeding downwardly at N'an angle, as would normally tbe-expected. It can be readily demonstrated that the greater the 'angle of theknifewith respect'to thetransverse axisfof s'the vehicle, the Ygreater the tendency for the -knife to complete the cut at the initial level. An additional advantage `of theangular placement 'of the "knife may lbe termed the slicing action as contrastedwith .the wcdging action7 peculiar to blades mounted transversely. Ithas-been found .thatlsuch angular orientation results in a ldecreased tendency to displace the beets Aduring the cutting process and .blades can be .usedfor alongerperiod before resharpening vbecomes necessary. It will .be` noted, however, .because .of `the -accessibilityof fthe baldes, that l0 replacement'or removalfor re-sharpening can readily be accomplished.

It has been found thatV the lower leaves of the beet, especially those in contact with the earth, .are limp .and ropy rather than crisp and therefore have more of ,a tendency to interfere .with proper operation of the topper than the leaves which are well clear of the ground. For this reason, it has been found desirable prior to the topping operation to cut the lower leaves from the beet ahead of .any'part of the mechanism that Amight become jammed with them. In the instant embodiment, `this is accomplished by means of coulters `!3.8 mountedon depending .Coulter brackets MD. While lsuch coulters are shown as being placed so as to come rather closely adjacentto .the outerl sides of the beet in each pair of rows, other arrangements may 'be used as required.

In order to transversely stabilize the Vtopping mechanism -as a Whole with respect to lthe tractor, a steering disc M2 is rigidly connected near 'the center of the horizontal bar "8U by means of the steering disc arm |44. As the toppingmechanism is drawn forward, thesteering disc rotates about a pivot |45 and penetrates lthe soil to a depth of, several inches. A nonrotating vrudder-like member may be .used lfor .this Ipurpose, but a disc has proved .to .be advantageous in practice.

In order more .fully to Vunderstand 4the relative movement .of the .knife .and the finder which takesplaceas theftopping mechanism strikes. a zbeet, reference .is made to Fig. 5. With the finder and the .knife .in .the at rest position, Vthe bottom or contact point of the finder -disc EAZI will descend @to fa .point 1.5@ which,gas ,will flater appear, iis .normally Ilocated ,on -the imid- .plane Simultaneously the knife vbladeiis @caused toassume *aposition'of rest at .point '15! which is'locatedfa short distance belowrpoint 1.5i). 'The yvertical distance between `points 150 vand 15'! .may,..for purposes.of convenience, be called the initial adjustmenti drawnfalong-a row of beets and the'iinderdisc i12-.I engages a beet 152, the nder disc-isswung :upwardly about the pivot point -I It to poi-nt i153. .At-"the'same time/the level of the knife at the center'line'of'the-disc changes, due'to the pivoting about point H8, moving to -a new point |54. Thus it is seen that in the process of stopping, the :knife moves both vertically and lhorizontally-with respect tothe finder; `and in `orderto produce a proper crown thickness fora given size of-beet, it is necessary that both the vertical and the horizontal movements of 'the knife with -respect `to the point of contact of `the iflnderifollow accurately formulated relationships.

With `regard to the vertical -motion, it has already been pointed outthat it is desirable under normal circumstancesfor the knife .to rise one inch asthe under rises 1.4.inches- The initial adjustment or vertical distance -between 4the lnder .andtheknife Ywhen the finder is-at the midplane (Fig. ll) has beenfound by experiment to be preferably .45 inch. While other initial adjustments, for example, .75 inch, might be usedunder certain circumstancesthe value-.of .45inch willserve as a basisforobtaining sample design data Assuming that lmovement ofthe finder and knife startsifromithe atirest position, itwill As the :topping :device lis appear obvious that the crown thickness C. T. may be given by the following expression:

If the nder rise is assumed to have a value I-I (the height of the crown of the beet above the lnidplane) and if the finder rise and knife rise are interrelated by the ratio 1.4:'1 mentioned above, the expression for crown thickness becomes the following:

Experiment has shown that the height of a beet above the midplane is equal to approximately .8 of the beet diameter D; thus the expression for the crown thickness may be given as:

The last column in the table Fig. gives various values of crown thickness as a function of the diameter which are obtainable using the above formulas. These values are used in determining the desired resultant path of the knife with respect to the finder.

Since it is necessary that the knife move horizontally with respect to the point of contact of the nder so that the knife may contact the `beet at the instant that the finder is at the high by the curvature of the beet crown. The combination of these three factors to determine the proper horizontal spacing or gap between the finder and the knife edge at the center line of the beet may be determined with reference to Fig. 9. It will be seen from the figure that the gap is equal to the radius R of the beet plus the lag due to the angularity of the knife minus the amount which it is necessary to advance the knife because of the curvature of the beet top. The expression for gap therefore becomes:

The lag is found by drawing a tangent 160 at the angle of the knife (in this case 45) from the outer diameter of the beet to the center line. For a beet having a two-inch radius, the lag can be shown, either mathematically or by construction, to be equal to .84 inch. In order to determine the crown curvature advance, it is helpful to draw an outline |62 of the beet profile, the height H ofthe profile being fixed by the fact that the height is equal to eight-tenths of beet diameter. The topping level is determined by the crown thickness (which for a fourinch beet is equal to 1.37 inches), and a construction line |64 is drawn at this level. A perpendicular line |66 which is drawn from the intersection of the line |64 and the profile |62 determines the magnitude of the crown curvature advance along the center line, in this case approximately 0.1 inch. The expression for gap, assuming a four-inch beet, therefore becomes:

Gap=2-}.84-0`.1=2.74 inches The table of Fig. 10 shows values for gap which have been worked out in the same manner for other diameters of beets. The way in which the data contained in the table of Fig. 10 may be utilized in the design of apparatus in accordance with our teachings is shown in Fig. 11. As a starting point in the design, a convenient length of finder arm |20 is chosen and a convenient location for the finder arm pivot ||6 determined. Choice of these two factors determines` an arc indicated in Fig. 11 between points |50 and |53. Starting at a level of zero elevation which in the practical embodiment is the midplane, equal increments of elevation 'are marked off. Since the height of a beet crown above the assumed zero level or midplane is eight-tenths of the maximum diameter of the beet, these increments of elevation are each made .8 inch. A point thus marked off on curve |50, |53 is the elevation to which the finder arm will rise for an average beet of the diameter indicated in the drawing.

It next becomes necessary to determine the location of the knife corresponding to each of the points marked off on the finder arm. For each point on finder arm curve, the knife will be located both downwardly and to the rear of the point of contact of the nder. The values of gap (see Fig. 10) corresponding to each beet diameter gives the horizontal displacement of the knife with respect to the nder while the values of crown thickness give the downward displacement of the knife with respect to the finder. There results, therefore, the curve of knife swing found between points |5| and |54 in Fig. 11. By using well known graphical methods it is possible to determine for practical purposes the length of the knife arm |23 and the location of the pivot ||8 to produce the required arc of movement.

A connecting link |3| is positively attached to connection points |3|a and |3|b located intermediate the ends of the finder arm |20 and the knife arm |23 to cause the knife at all times to occupy a predetermined position with respect to the nder. The relation of this connecting link to each arm |20, |23 is in accordance with the required or desired'ratio of knife movement to finder movement (see Fig. 11).

Beet top elevator Subsequently to the topping operation, the beet tops are picked up from the ground and elevated to the conveyor by means of the elevator shown in Fig. 2 and indicated generally by the numeral 160. The elevator frame is composed of longitudinal members |62 and |63 at the ends of which are mounted lan upper shaft |64 and a lower shaft |65. The weight of the elevator is borne by lower brackets |66 and |68 detachably connecting the longitudinal members |62 and |63 with the horizontal supporting bar 80, the brackets being longitudinally adjustable through such means as bolt yand slot connections. Support at the other end is supplied by arms 13 which are pivoted on the conveying-supporting unit |5.

Mounted on the shaft |65 is a rotating cylinder |10 with radially projecting fingers |1|. The cylinder is rotated by conveyor chains |12 and |13 driven by the upper shaft |64. The chains are interconnected at intervals by slats |15. Flexible extensions |16, which may be of leather or the like, bridge the spaces between the slats |15 to form an elevator apron. An elevator of this construction is particularly adapted to the elevating of beet tops since the flexible extenvverse shaft |82.

`1'3 sions |16 result-in a whipping action `at the-top of vthe .elevator and'prevent the foliage from being wound about the ,lowerl shaft |65.

In operation, as the cylinder rotates, the lingers arev caused to pass between the tinesof a rake Vil. vThis results in the depositing. of .they tops on the elevator apron land their'subsequent depositing on the conveyor 3|.

Fig; 8 shows the means used in the presentinstance for the transmission of Vpower to thebe'et top elevatorand conveyor. It will be noted that rotation of the. shaft 'Hi driven by thepowerr takeoi sheave l2 causes rotation` of .a set of bevel gears `Iiiiland, consequently-rotation'ofa trans- Power is Itransmitted from the shaft |82 to the elevating chains |72 and |"|3'via a-'flrst chain |83, an intermediate shaft ldfand a second .chain |85. Adjustment of-thefspeed of the-elevator chain may be effected by choice of sprockets. of the `proper size mounted on the shaft |34.

While the operation ofthe beet topperA and elevatingv mechanism will be clear from the foregoing, the operation will be briefly summarized as follows: As .the'tractor'is driven along abeet row with its ywheels in Ithe-furrows or ditches, thexgauging runnersV |33 ride along the crest of the row. rllhis vmaintains the pivot-supporting member Htl at an elevation which is proportional to.` the yelevation of the midplane. disc I2 l, which `iscentered. upon the beet by the action of the gauging runners, engages the crowns of: thebeetsand; as a result of the action ofithe linkage .associating the knife and thev finder disc, moves the knife.` |35 to the predetermined point of elevation. and horizontal displacement. ,Thel severed tops arey immediately thereafter picked up by the elevator., deposited upon the con'- veyorand ejected onto a vehicle 'traveling along'- side Vthe tractor.

Digging unit Fig. 3 shows a digger. and elevatorconstructed in accordance with our invention. .Thefdevice'is adapted to idigy beets in* two rows. simultaneously and' includestworduplicate;sets of digger. appara'- tusffor accomplishing this .function. Becausei of such duplication, :only one perspectiveview'ofthe device is necessary to understand the' structure and operation; accordingly; only thev assembly r readily visible in Fig. fwilllbe discussed.

The main supporting v,member for the dig-ger and its associated elevatori is athe vl'lorizontal bar 226 suspended from Ythe Ilower draft links"2|llv and 2 i .by means of `the rigidlyfmounted tabs 202|'- and 282 Arespectively and connectedyto the-*upper link Zrby means `of vvthe v.vertical arm 2il3. At Vthe ends of the bar 221B and rigidly affixed thereto. are trailingextensions 294. Each :ofthezlatter serve to support the-plow-assernblysupporting arm 206 bya pivotal connection 295 on the projectingportion 2li? ofthe arm. A. crossrbarwehwhichrigidly interconnects a-supportingarm 206A oneach side of Ythe vehicle insuresfthfat-both sets ofrdigger apparatus are raised :and Ylowered-iin iunison.

Attached tothe supportingcross fbar'2'9' are verticaltarms 2| Eiwhie-h 'serve-to support y'the cooperating., plow blades 2||v and- 242i Trailing ngers 2f|3 and=23|4,.whi:ch are respectively asson ciated with the plow" blad-es', andthef guiding fingers f2 guide thebeets during-rearward movement after they. arey removed frorn-theV earth. The plowbla'd'es Ztl and 2 l2I are normally lowered into the ground lby'reasonl ofthe 1lowering of the lower linkssZ lfand2| land, uponf forward-move# The .finder `showriat |52.

ment of the'vehicle, engage aebeet such as kthat Since the plow blades 2| and 2 |2 vtaken Ytogether form a narrowing V-shaped notch, a beet is gradually pried out of the ground and onto the trailing fingers 2 |3r and 2 |4.

As the beets pass along the trailing ngers, they are engaged'by a conveyor wheel 22|! pivoted .about a shaft 23B which, in the present embodiment, has a double row of radially-extending rlChe conveyor wheel 22B is rotated at a ,peripheral speed which may be approximately equal tothe forward speed of the vehicle. By

`reason of such rotation and the decreasing clear- .fingers 2|3 and 2|l` and the wheel 220 remains constant for all plow levels.

YAfter `being carried approximately one-half a revolution by the conveyor wheel 222, the beets are engagedby the fingers 222which are tangen- -tiallylocated with respect to the conveyor wheel and arranged gradually to disengage the beets from the spikes 22 i. As the beets are freed from the spikes 22 they are engaged by defiectors 223 ywhich are curved inwardly,A tending to urge the beetsfcentrally into the hopper 221.

Anelevator indicated generallyby the numeral 229 removes the beets from the hopper. The elevator frame includes two longitudinal members 22E-'to whichA are fastened, at the upperand lower ends respectively, shafts 228 and 230. As previou'sly noted, the lowerv shaft 235! serves as anaxis of rotation for the-conveyor-wheel 22|]` and for-the conveyor chain as well as serving as a point of pivotal support for `the plowassembly supporting arms ZDB.

The raising ofthe beets in the elevator is effected by'a movement of conveyor chains 234 and 265 driving cleatsl 236fastened to the chains at intervals; The conveyor chains 234 and 235 are driven bythe upper shaft 223i which is in turn drivenI by the' belt 1|, through the transverse shaft |82 `and a chain 24 During the process of elevation, dirt is effectively removed from the beetsby reason of their tumbling against a stationary lattice 242; The beets are prevented from being dislodged from the elevator by side guards 243 and 244 and are directed onto the con'- veyor't Aby the deflecting cover 24.5 attached near theupper end of the guards.

ln order to cause rotation of the conveyor wheel22llatfthe proper speed with respect to the-chains ofthe elevator, it is necessary that a speed changing device be incorporated between the shaft Zittend the conveyor wheel. In the present embodiment, speed changing is accomplished by auxiliary sprocket wheels and chains. Av first ,sprocket wheel 24B is rigidly. coupled tothe shaft 236. This sprocket wheel drives a sprocket ,chain 2&5 which is in turn engaged with a second sprocket lwheel 25|. Mounted on the same shaft 252 as thesecond sprocket wheel. is a smaller sprocket wheel `253 whichdrives ase'cond sprocket chain 254. The latter engages a fourth sprocket wheel 255 which is engaged'to andlturns at thev saine speed as, tlfeconveyor' wheel 22|).

The conveyor wheel at the other side of the digger is driven by means of the shaft 252 through the medium of a similar sprocket wheel 253, a similar sprocket chain 25d, and a similar sprocket wheel 255. These components, although hidden from view in Fig. 3, need not be shown, as their action is identical to the action of the correspondingly numbered parts observable in Fig. 3. Mechanical power therefore flows to the conveyor wheels 22 by the following route: power take-ofi? l2, belt 1|, shaft |82, chain 24|, shaft 228, chains 234 and 235, shaft 235, sprocket 248, chain 250, shaft 252, sprockets 253, chains 254, sprockets 255.

The means for coupling the upper end of the beet elevator to the conveying-supporting structure is substantially the same as in the case of the beet top elevator in that the arms 241 attached to the members 225 are pivoted on the transverse shaft |82.

Because of the very light draft load involved in the use of the digger plows 2| l, 2|2 (Fig. 3), particularly under loose soil conditions, it is not feasible to control their depth of penetration by the conventional Ferguson System arrangement, in which the hydraulic lift on the tractor is caused to raise and lower the implement automatically to retain the draft load substantially constant. In other words, the draft loads involved may be too small to operate the spring "I1 for any reasonable size of the latter, To overcome that difficulty, an actuating arrangement is provided for the automatic controls on the tractor which is operable at a position of the implement predetermined by adjustment rather than by the draft load on the implement. In brief, the arrangement is such that the downward vertical movement of the digger unit causes a portion of its weight to be applied through a leverage system to arbitrarily load the control spring 11 at a preselected period and thereby to stop further lowering. Thus, the lowermost limit o1" the unit, and of the digger plows in the soil, may be adjustably set.

As to the particular arrangement illustrated for applying force to the control spring 11, it will be seen upon inspection of Fig. 3 that the yoke 74 is connected to the longitudinal members 225 of the elevator by means of a coupling consisting of a pin 240 which bottoms in a cooperating slot 245. The yoke 74 terminates in a threadedly telescoping rod 14a which pivotally engages side extensions 15 on a rocker arm 16. The latter is rocked forward by loading on the yoke 74, when pin 24B bottoms in slot 245 to compress the control spring 11.

It will be obvious from Fig. 3 that inward movement of the yoke "I4 and the rod 14a transmitting force to extensions i5, which provide considerable leverage, causes inward rotation of the rocker arm 'I6 and compression of the control spring Tl. Lowering of the lower links, tool bar, plow blades and elevator and the concurrent inward movement of the rocker arm 16 will normally take place under the effect of gravity until the rocker arm is displaced sufliciently so as to cause the main control valve (not shown) of the hydraulic system to shift and prevent further dropping of the links. The point in the path of rotation of the rocker arm at which such valve movement takes place may be predetermined within limits by adjustment of the quadrant lever 24.

Likewise if the plows should for any reason be deflected upwardly, such upward movement would cause an outward swinging of the elevator, a removal of the force exerted by the weight of the elevator upon the control spring 11 and outward swinging of the rocker arm 16. Movement of the rocker arm outwardly beyond a predetermined point causes control valve of the hydraulic system to be shifted in such a manner as to cause the lower links to drop and the plows to penetrate more deeply. Thus it is seen that an equilibrium level of the lower links, plows, and elevator is established in which the rocker arm is partially displaced and the control spring partially compressed.

The above mechanism, producing a positioning control which effectively counteracts any extraneous forces tending to displace the digger plows from a preset depth, is set forth in greater detail in the copending sole application of Leon R. McRobert, Serial No. 743,186 filed April 22, 1947 as a division of the instant application and to which reference is made.

The linkages shown associated with the plow assembly are particularly Well adapted for removing the plows from the earth as required for transportation. This is readily accomplished merely by throwing the quad-rant lever 24 to raise the lower links 20 and 2| to an extreme upward position. Upward movement of the lower links 20 and 2| causes upward movement of the horizontal cross bar 200, upward movement of the plow assembly supporting arm 206 and the consequent movement of the plow assembly upwardly about the shaft 230 as a pivot to an out of the way position where the assembly is tucked in ahead of the then elevated conveyor wheel, The simultaneous upward rotation of the trailing lingers causes them to be clear of the ground and to present a protecting tapered surface to any exceptionally high obstructions encountered during transportation.

Although the operation of the beet digger will be apparent from the foregoing, the operation may be summarized as follows: As the digger is drawn forward, the plows 2|| and 2|2 traveling below the surface at a predetermined level engage the lower wedge-shaped surface of a beet and exert a wedging or camming elect thereon to force the beet from the ground onto the trailing fingers 2|3 and 2| 4. As the conveyor wheel 220 rotates at approximately ground speed, the spikes 22| are inserted into the beet and the beet is carried away from the trailing fingers and into'contact with a pair of tangentially-extending lingers 222 which remove the beet from the spikes 22|. Deflecting rods cause the beets to vbe directed into the hopper 221 from which they are removed by the cleats 236 of the elevator. During the upward movement, dirt is removed by the abrasive action of the lattice 242 and the beets are deposited on the belt 43 of the conveyor for disposal into an accompanying truck or similar vehicle alongside the tractor.

We claim as our invention:

l. In a beet topping device, a parallelogram linkage arranged for vertical movement and having vertical and horizontal members, a first vertical member adapted to be supported at a predetermined level with respect to the ditches between beet rows, a gauging member adapted to contact the ridge between adjacent ditches, a second vertical member associated with said gauging member, said second vertical member being disposed in spaced apart trailed relation with said first vertical member, horizontal links connecting said vertical members, pivot-supporting means con,`

nected to at least one of said horizontal links at a point between said vertical members, a finder arm to engage the crown of beets to be harvested, a knife arm utilized in the cutting of said beets connected in operative relation with respect to said finder arm, said nder arm and said knife arm being pivoted to said pivot-supporting means.

2. In a beet topper the combination comprising a nder arm having a finder at one end thereof, means for trailingly pivoting said finder arm on a tractor at its other end so that it is free to swing vertically as the finder is drawn along the tops of the beets in a row, a knife arm having a knife at one end thereof, means for trailingly pivoting said knife arm on a tractor at its other end for vertical swinging movement of the knife, and a linkage disposed in positively connected relation between connection points respectively located intermediate the ends of each of said arms, said connection points being so located that each increment of swing of the finder will be accompanied by a lesser increment of swing of the knife to adjust the latter to a predetermined cutting level with respect to the finder, said knife arm being pivoted at a point upwardly and rearwardly of the point of pivoting of said finder.

3. In a beet topper the combination comprising a finder arm having a finder at one end thereof, means for trailingly pivoting said finder arm on a tractor at its other end so that it is free to swing vertically as the finder is drawn along the tops of the beets in a row, a knife arm having a knife at one end thereof, means for trailingly pivoting said knife arm on a tractor at its other end for vertical swinging movement of the knife, said knife arm being pivoted at a point upwardly and rearwardly of the point of pivoting of said finder and having a greater radial length than the latter, and a rigid link interposed between pivotal connection points adjacent the midportions of said arms, said link connection points being located on said arms at radii such that the vertical displacement of the knife will be less than that of the finder and the rearward displacement of the knife will exceed that of the finder.

4. In a beet topper the combination comprising a finder arm having a finder at one end thereof, means for trailingly pivoting said finder arm on a tractor at its other end so that it is free to swing vertically as the finder is drawn along the tops of the beets in a row, a knife arm having a knife at one end thereof, means for trailingly pivoting said knife arm on a tractor at its other end at a point located upwardly and rearwardly ofthe finder pivot point for vertical swinging movement of the knife, the radial length of the knife arm being greater than the radial length of the finder arm, and a rigid link pivotally interconnecting the midportions of said arms so that a vertical swing of the finder will be accompanied by a corresponding vertical swing of the knife, the pivot points of said arms and said rigid connecting link defining a linkage wherein the horizontal gap between said finder and knife is susceptible of increasing progressively with beet size, said linkage being susceptible of effecting entry of the knife to take place when the finder is substantially centered on the crown of a beet.

5. In a beet topper the combination comprising a finder arm having a nder at one end thereof, means for trailingly pivoting said finder arm on a tractor at its other end so that it is free to swing vertically as the finder is drawn along the tops of the beets in a row, a knife arm having a knife at one end thereof, means for trailingly pivoting said knife arm on a tractor at its other end at a point located upwardly and rearwardly of the finder pivot point for vertical swinging movement of the knife, said knife arm being of greater length than said finder arm, and a link interconnecting the midportions of said arms so that the upward swing of the finder is accompanied by upward swing of the knife to adjust `the latter to a predetermined cutting level, said link being shorter than the distance between the pivot points of said knife arm and said finder arm but connected at approximately the same radii on both of said arms so that the spacing between said finder and knife both horizontally and vertically increases progressively with the size of the beet.

6. In a beet topper the combination comprising a finder arm having a finder at one end thereof, means for trailingly pivoting said finder arm on a tractor at its other end so that it is free to swing vertically as the finder is drawn along the tops of the beets in a row, a knife arm having a knife at one end thereof, means for trailingly pivoting said knife` arm on a tractor at its other end for Vertical swinging movement of the knife, said knife arm having a greater radial dimension than said finder arm, the pivot point of said knife arm being located upwardly and rearwardly of the pivot point for said finder arm, a link of lesser length than the distance between the pivot points of said arms and disposed in pivotally attached relation with their midportions, said link being connected at such radii on said arms that movement of the same in response to increasing beet size will increase progressively the horizontal gap between said finder and knife enabling initial entry of the knife to take place when the nder is centered on the crown of a beet, said knife having a sharp leading edge and a relatively wide horizontal blade portion `so that cutting is stablx7 maintained at the level of initial entry.

7. In a beet topping device, the combination comprising a parallelogram linkage having a first generally Vertical member, means for supporting said member at a predetermined level with respect to the ditches between beet rows, a second `generally vertical member disposed in spaced-apart trailed relation with said first vertical member, and vertically spaced generally horizontal links connecting said vertical members, a nder to engage the crowns of beets to be harvested, a knife arm utilized in the cutting of the beets connected in operative relation with respect to said finder, pivotal supporting means for connecting said knife arm to said parallelogram linkage, and a gauging member connected to said linkage for contacting the ridge between adjacent ditches to adjust the height of said pivotal supporting means.

8. In a beet topping device, the combination comprising a finder arm to engage the crowns of beets to be harvested, a knife arm for severing the tops of said beets connected in operative relation with respect to said finder arm, vertically movable means pivotally supporting said arms, and means for supporting said vertically movable means including a first generally vertical member, means for supporting said first member at a predetermined level with respect to the ditches between beet rows, a second generally vertical member disposed in spaced-apart trailed relationship to said first member, vertically spaced .generally horizontal links connected hetween .said vertical members, and a gauging member associated with .said second vertical member for contacting the ridge between adjacent .ditches to adjust the height of said vertically movable means.

9. In a beet topping device for use with a tractor having laterally spaced trailingly vpivoted lower links and a trailingly pivoted upper link, the combination `comprising a nder arm to engage .the crowns of Ybeets to be harvested, a knife arm for severing the tops of said beets connected in operative relation with respect to said finder arm, vertically movable means for pivotally supporting said arms, and means for supporting said vertically movable means including `a first generally vertical member, means for connecting said vertical member to the upper and lower links on the tractor to .support said rst member at a predetermined level with respect to the ditches between beet rows, a gauging member for contacting the ridge ,between adjacent ditches to adjust the height of said vertically movable means, `a second generally vertical member associated with said gauging member and disposed in spaced-apart, trailed relation with said first member, and vertically spaced 20 horizontal :links `connecting: said .rst and `second References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 833,456 Goodfellow Oct. 16, 1906 873,040 Goodfellow Dec. 10 1907 922,084 Carroll May'18. 1909 1,257,168 Wilson Feb. 19, 1918 1,282,657 Tussing Oct. 22, 1918 l1,369,721 `W i1s 0n Feb. 2 2, 1921 1,533,672 Stockstill Apr. 14, 1925 1,585,727 vLeitch e Mey 2 5, 1926 1,592,859 Leitch July 20, 1926 2,184,422 Graham Dec. 26, 1939 2,214,949 Zuckerman Sept. 17, 1940 2,305,254 Hirschkorn Dec. 15, 1942 2,336,623 Loucks Dec. 14, 1943 2,337,698 Walz Dec. 28, 1943 2,350,173 Louc'ks May 30, 1944 2,369,850 Powers Feb. 20, 1945 2,404,629 Grin July 23, 1946 2,415,013 Kubitz Jan. 28, 1947 2,429,044 Bassett Oct. 14, 1947 

